Apparatus for sensing various types of photographic color films and for converting an image into a video signal are well known in the art. With the development of relatively low cost, reliable solid state image sensor there has been increasing interest in the development of devices such as film video players for displaying film images such as those present on color slides or color negatives on television monitors and receivers. With the availability of such sensors there has arisen an interest in composing a video image corresponding to only a portion of a film image and for displaying or recording such a video image.
A primary reason for the interest in composing selected video images constituting a portion of a film image is that the resolution of the commonly used photographic film formats is substantially greater than standard television resolution by factors of approximately four to ten times. As will be appreciated, the full available resolution of these film formats is not effectively used at normal magnification where the full frame film image substantially fills the solid state image sensor so that the video image effectively just fills the display of the television monitor or receiver. The excess resolution available in these film formats can be advantageously utilized by providing a film video player with means such as zoom optics for selectively changing the magnification of the video image and thus the displayed image with respect to the film image. Since in its magnified form the video image and resultant display constitutes only a portion of film frame image, it is desirable to be able to effect relative vertical and horizontal translation between the film image and the video image. More advanced composing or editing functions can be carried out where it is possible to effect relative rotation between the film image and the video image.
A common approach in the design of film video players of this type contemplates the use of fixed apparatus for mounting a slide or film negative presenting a film image and a fixed sensor spaced a distance therefrom along the optical axis of the system. Interposed between the fixed film image and fixed sensor is a multi-group variable focal length lens wherein one of the lens elements is movable axially along the optical axis to vary the focal length of the lens and thus provide a zoom capability. Multi-group variable focal length lenses of this type suffer the disadvantage that they are relatively expensive. Such multi-group variable focal length lenses also have additional manufacturing and assembly disadvantages when incorporated into a video player.
U.S. application Ser. No. 143,661 for "Film Video Player Apparatus", filed of even date, proposes a film video player employing a fixed focal length lens. The disclosed system creates a selectively composed video signal from a photographic film image by moving the lens and sensor axially of the optical axis of the system, by translating the sensor in two perpendicular directions relative to the film frame image, and by rotating the sensor relative to the film frame image. A problem arising in such a system involves the necessity for maintaining various wiring interconnections between the sensor and related signal processing means for transmitting timing, video and power signals between the sensor and signal processing means mounted on a relatively fixed portion of the chassis of the video player at all times. Thus, there is need for a multi-signal flexible cable capable of maintaining an interconnection between a sensor and video player chassis during movement of the sensor axially, translationally and rotationally relative to the optical axis of the video player with attendant motion relative to the signal processing means.
It is known in the electrical arts to employ a coiled cable between concentric cylindrical members of different sizes in lieu of wiper contacts or rings which may be subject to damage or operating failures after extended operating periods. In this respect, ribbon cable is wound in a plurality of circumferential revolutions in the area between the outside diameter of the interior cylindrical member and the inside diameter of the outer cylindrical member. Such devices do not, however, contemplate and would not permit substantial axial or translator motion between the cylindrical members.
It is also known in the art to employ flexible printed circuit interconnecting cable to join two sections of collapsible camera configurations in such a manner as to effect flex of the cable in a gradual manner over an extended length of the cable to accommodate pivotal motion between the camera sections without overflexing the printed circuit cable. Additionally, it is known to employ a flexible circuit interconnecting cable wherein flexure is achieved in a plurality of planes by cutting the substrate longitudinally between conductors and thereafter twisting opposed end segments of the assembly to achieve a plurality of helical turns in the cable to provide flexural planes for desired relative motion between the two ends of the cable. Such flexible cable wherein the substrate is cut longitudinally between conductors may advantageously be provided with a sleeve of flexible material for mechanical protection and constraint.
In the use of flexible cables wherein signal carrying lines are bounded by conductive ground planes to reduce the effects of spurious signals or noise, it is commonly necessary to effect impedance matching between the flexible cable and a member interconnecting therewith, such as for example in the video apparatus arts a standard 75 ohm coaxial cable. Normally, a signal carrier would have a cross-sectional area in relation to the cross-sectional area of the ground planes which would produce a lesser impedance than such a coaxial cable connection. A conventional method to achieve impedance matching contemplates a reduction of the cross-sectional area of the signal carriers relative to the ground planes. In an application of this nature, however, reduction in cross-sectional area of the signal carrier would tend to reduce its area to an extent that its elastic limit might be exceeded or it would be subject to fatigue failure upon repeated flexing if the cross-sectional area of the signal carrier were reduced. Thus, a problem is presented in employing prior art teachings wherein it is necessary to effect axial, translational and rotational motion of one of two members connected by a flexible cable while achieving desired impedance matching characteristics with an interconnected coaxial cable without reducing the physical characteristics of the signal carrying members to an extent that they may be prone to mechanical failure upon the requisite flexing of the cable.